The work to be continued in the 1975-1976 grant period consists of (1) experiments on the optical properties of lysozyme including studies of a fluorescent probe; (2) Examination of the nature of the interaction of lactate dehydrogenase and malate dehydrogenase with NADH, NAD, and substrate analogs such as trifluorolactate; (3) Studies on the self-association of insulin at acid and neutral pH using thermochemical methods; (4) Heat capacity measurements on protein solutions and on hydrated solid protein samples aimed at examining protein solvation; (5) Calculations of the surface properties of proteins based upon cyrstal structure information. BIBLIOGRAPHIC REFERENCES: Reaction of N-Acetylglucosamine Oligosaccharides with Lysozyme. Temperature, pH, and Solvent Deuterium Isotope Effects. Equilibrium, Steady-State and Pre-Steady-State Measurements, S.K. Banerjee, E. Holler, G.P. Hess and J.A. Rupley, J. Biol. Chem. 250, 4355 (1975). The Circular Dichroism of Lysozyme, F. Tanaka, L.S. Forster, P.K. Pal and J.A. Rupley, J. Biol. Chem. 250, 6977 (1975).